Citing a low crop yield, Anheuser-Busch InBev has cut off outside access to South African hops, allocating the vast majority of available acreage for use in its own Castle Lager and Castle Light brands.

The world’s largest beer company is able to essentially monopolize the nation’s hop yield, one of the least-used among U.S. craft brewers until most recently, because, as part of its mega-merger with SABMiller, it also took control of SAB Hop Farms, South Africa’s leading hops producer.

The move to bring the near entirety of a nation’s hop crop under its own umbrella, of course, has inspired derision from American craft brewers, which have of late taken a liking to brewing with South African hop varietals. Traditionally, SA hops are of the high-alpha varieties, whereas newer varietals are more aromatic and flavorful in the vein of progressive craft beers. Indeed, demand for unique varietals such as African Queen and Southern Passion has grown in recent years, both in the United States and in other non-African countries, as sources in darling hop regions like New Zealand become increasingly competitive even among craft brewers.

On Wednesday, ZA Hops—a Colorado-based importer of South African hops—sent a memo to customers alleging that ABI is “commandeering” all of South Africa’s hops to be sold internally to its own High End brands, such as Goose Island, 10 Barrel, and, as of last week, Wicked Weed. His words read as somewhat intentional towards ABI’s intent of being non-competitive.

“This is a shocking turn of events, though commensurate with ABI’s business practices, and devastating to my company,” ZA owner Greg Crum wrote in the memo sent to brewer customers. “Yet another blow to craft beer.”

It’s worth noting again that these same fields were formerly owned by SAB Miller.

AB InBev, meanwhile, disputes that it’s cutting access specifically to benefit its High End portfolio. Rather, the company says that, because South Africa “suffered a low yield” this year, the vast majority of the hops will instead be used in its own South African brands. In turn, the company says less than 5% of the South African hop yield is available for use by AB breweries outside of the country.

“Knowing the high demand for South African hops locally and abroad, we are working to expand local hop acreage,” Willy Buholzer, global hops procurement director at AB InBev, tells GBH. “Depending on the 2018 crop outcome, we may once again be able to sell more hops to breweries outside of South Africa.”

That attempt at clarification though came only after a number of small U.S. brewers took to social media to slam the behemoth beer maker for what they maintain is nothing but an attempt to control the chain of resources at the expense of much smaller competition. It's a theme that, following the Wicked Weed acquisition, has never been more prevalent amongst American craft beer makers and consumers.

Many specifically latched onto the piece of the ZA Hops memo suggesting AB InBev would be allocating the hops for use in its own “High End” portfolio, thereby giving independent breweries and their supporters another reason to oppose acquisitions in the craft space.

Indeed, craft brewers are continuously looking for the next cool hop. Larger craft brewers go so far as to develop proprietary varietal that they themselves have control over in much the same way. Resources are becoming a battleground between brewers of all types and sizes.

This doesn’t merely affect U.S. brewers either, as other international craft beer makers have experimented with South African hops. Cloudwater, of Manchester, England, is one of them. Reached by GBH, co-founder and managing director Paul Jones says he believes the move by AB InBev suggests to him the company is “on the ropes, they’re running out of ideas.”

“It displays an embarrassing shortsightedness and weakness that the craftier side of the industry will have no problem stepping over,” Jones tells GBH. “We’re not the sum of our ingredients, we’re the sum of our ideas. Pity those that think otherwise.”

But there are real ramifications here. For starters, this is a death knell for ZA Hops, which dealt exclusively in South African hops. In the memo he sent, Crum says he’s now looking into the financial feasibility of importing wine and spirits barrels from the country. But this initiative kills his company, at least as it exists today. Reached by GBH, Crum declined to comment.

And though South Africa doesn’t produce a lot of hops, what they do make has become increasingly popular among and sought after by craft brewers in the U.S. looking to experiment with something new. In addition to those previously mentioned, Firestone Walker, Creature Comforts, Proclamation Ale Co., Other Half, and Monkish are among the renowned breweries that have taken to utilizing South African hops in their beers.

Cerebral Brewing of Denver is another. The company started working with ZA Hops this past year, and subsequently released a series of IPAs showcasing N1/69—the aroma for which is described as “Kool-Aid, Juicy Fruit, mango, citrus, plums, dank, and pungent”—and XJA2/436, which is described as “bergamot citrus, lemon, candied papaya, ripe cantaloupe, gooseberries, resin, and tobacco.”

Sean Buchan, company owner and head brewer, says the two beers (Letters & Numbers: N1/69 and Letters & Numbers: XJA2/436) “were some of my favorite hoppy beers we made last year.”

The company says it has two more beers coming out this month highlighting the varietals: Cheat Code, a 7.4% IPA featuring N1/69 as well as noteworthy American breeds Galaxy, El Dorado, and Mosaic, and Ripping Through Dimensions, a Brett Saison dry-hopped with XJA2/436 and Galaxy.

“We have a little left to play with of these varietals,” he says, “but they’ll go pretty quickly.”

As such, he was looking forward to getting more next year. He says the company was too late to the game to get some of the “sexier” varietals on the first go round. But he had contracted for 440 pounds of both African Queen and Southern Passion for next year. Now, though, the company will have to wait and see what AB InBev decides to do with a more fruitful yield before it can experiment further.